The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
A cutting tool assembly is configured to receive an input torque from a mating tool driver assembly. The cutting tool assembly includes at least one cutting edge upon a tool tip that utilizes the input torque to cut a workpiece.
U.S. Pat. No. 5,468,102 titled “Milling Tool Holder” for which the present applicant was the sole inventor discloses one previously known method and apparatus for securing a cutting tool assembly to a mating tool driver and is included herein by reference. According to this reference, a tool holder portion of a cutting tool assembly is provided with a cylindrical section. A pair of conically shaped screw cavities can be formed in opposite sides of the cylindrical section, such that when the cylindrical portion is inserted within a mating cylindrical cavity in a mating tool driver, a pair of threaded fasteners can be used to lock the tool holder portion into place. This design has a number of advantages, however, it also includes a drawback that the screws together bear a large or majority portion of the input torque applied to the tool through the mating tool driver. This input torque applied to the fasteners can damage the fasteners, which can have a number of adverse affects including making disassembly of the tool difficult or impossible. Some tools must be destroyed when the fasteners deform too much after rough use.
U.S. Pat. No. 8,360,699 titled “Cutting Tool Assembly with an Eccentric Drive Member” for which the present applicant was the sole inventor discloses one previously known method and apparatus for securing a cutting tool assembly to a mating tool driver and is included herein by reference. According to this reference, a tool holder portion of a cutting tool assembly is provided with a first conical portion attached to a second eccentric or oval shaped drive member portion, with a third cylindrical portion including a locking mechanism. The eccentric drive member provides a benefit, enabling the tool to be rotated within the mating tool driver, with surfaces of the eccentric drive member aligning to a mating oval shaped cavity. In this way, the eccentric drive member can transmit torque from the mating tool driver to the cutting tool assembly without deforming a plurality of set screws. This design has a number of advantages, however, it also includes a drawback that the conical section and a mating conical cavity in the mating tool driver must be constructed to tight tolerances in order to ensure proper tool alignment. Such tight tolerances slow manufacturing time of the cutting tool assembly and introduce a source of tool malfunction, in that any small deformity or damage to the conical section can invalidate the tool or require intensive repair of the conical section to realign the tool. Further, because the conical section, by increasing in size toward the flat collar section joining the tool holder portion to the rest of the cutting tool assembly body, the size of that flat collar is reduced. This increases an ability of the tool to cant or tilt slightly within the cavity of the mating tool driver. Combined with tool strain created while cutting through a work piece, this tilt can lock the cutting tool assembly within the mating tool driver. As a result, in order to remove the cutting tool assembly from the mating tool driver, one must frequently use a hammer to knock the cutting tool assembly loose from the mating tool driver, frequently causing damage or increased wear to the cutting tool assembly.